1. Field of the Invention
This invention relates generally to human powered vehicles and, more particularly, to vehicles of the foot-pedal type having an operator in a partially reclined position. Specifically, the present invention relates to human powered vehicles with drive mechanisms having significantly improved mechanical advantages.
2. Description of the Prior Art
Human powered vehicles of a wide variety of different types have been in existence for centuries. Of these, the conventional bicycle has perhaps been the most successful and widely accepted form of human powered vehicle. Despite the wide acceptance and use of traditional bicycles, such bicycles have a number of disadvantages which make improvements to its construction and/or design highly desirable. For example, the rotary pedals which are generally located at a position beneath the operator's seat are not well adapted for achieving maximum performance in transmitting power from the rider to the drive train and are also limited in their capacity for sudden changes in speed and direction. During the period in which the cranks of the bicycle pedals are aligned with riders legs, no torque is transmitted from the rider to the power train. In addition, the steering of a conventional bicycle is limited to steering the front wheel alone, while the braking is limited to slowing the rotation of one or both wheels.
Numerous attempts have been made over the years to try and overcome some of the above delineated obstacles and disadvantages of the conventional bicycle. U.S. Pat. Nos. 849,342, 2,638,359 and 4,379,566 are all directed to conventional two-wheel bicycles which are adapted in order to improve mechanical advantages in the torque applied by the operator of the vehicle, and in the efficiency of conversion of a vehicle operator's leg motion through the pedals to the drive train of the bicycle.
U.S. Pat. Nos. 1,562,553, 1,876,859 and 4,052,912 are all directed to variations of a traditional bicycle by including three or four wheels to the vehicle for improved stability as well as changes to the drive linkage mechanisms and the like in attempts to improve the transmittal of energy from the operator to the ultimate driving wheel or wheels.
In recent years, efforts to improve the efficiency of bicycles have taken several directions. One direction of thought deals with the improvement of gearing mechanisms to improve the efficiency of existing drive systems. Another major trend is in the development of recumbent bicycles wherein the operator is positioned in a reclined position moving their legs in a direction substantially parallel with the direction of movement of the vehicle. This also has permitted streamlining of the vehicle which, when in combination with improved gearing mechanisms, has developed recumbent bicycles capable of exceptionally high speeds. U.S. Pat. No. 4,592,563 disclosed one such recumbent vehicle which uses a traditional rotary pedal crank arrangement. U.S. Pat. No. 4,708,356 discloses another recumbent vehicle arrangement requiring two operators and includes a very sophisticated and complicated gearing mechanism which interconnects both foot pedals and arm levers used to power the vehicle. Other potential forms of human powered vehicles include water craft and various types of air craft. However, they have not yet been feasible due to lack of energy transformation efficiencies coupled with ultra-light weight construction. Thus, there remains a need for a human powered vehicle having high mechanical efficiencies operable by one operator, which vehicle could be in the form of a recumbent bicycle or other vehicles which, if the efficiencies are sufficiently high, are capable of taking the form of helicopters, airplanes, water craft and the like.